The purpose of this application from Dr. Monoz at the Johns Hopkins University School of Public Health, is to establish a WIHS Data Management and Analysis Center (WDMAC)that will provide leadership in data management, study coordination and analytical methodology and thereby enhance the quality and validity of the data and the scientific research. The WDMAC will 1.Provide leadership in the design, analysis and presentation of the WISH studies and develop novel statistical and epidemiologic methodology. A core component will be to collaborate in the design sign of HIV pathogenesis projects. 2. Establish and operate a data management system that encompasses data entry transmission, documentation, editing, storage and transfer of biological specimens at a national repository. 3) To coordinate research initiatives and facilitate communication, coordinate protocol revisions and produce study-wide profiles of cohort characteristics (the WIHS Dossier the study data base and research initiatives (the WDMAC Report), and publications (the WIHS Archives). 4. To implement a quality assurance program that integrates expertise in data management study, coordination, statistical methodology and scientific disciplines. This program will include training. 5 To provide an efficient transition from the current coordinating center and to facilitate the transition to a subsequent coordinating center, if required.